Cannot Deselect objects in when other objects are behind the selected Ones
When you right click on an area with multiple objects, blender will cycle among these object.

You have several possibilities to overcome your issue:


changing the view a little (by panning around but, even more effectively, by zooming in) in order to free up that portion of space, and make a less ambiguous click. Note: in wireframe view, the objects you select are the ones whose edges - not faces/volume - are near your mouse pointer.
using the Outliner window, that is the top-right window in the default worktable
using Undo: Ctrl+Z. The Undo history contains selections as well! Note: there are separate histories for Object and Edit mode.
[Edit, thanks Mr Zak] you can use the other selection methods that you have mentioned (B, C), provided that you then use MMB for the selection to make it subtractive. 


However, the "selection by depth" menu Alt+RMB can help you make more precise selections.